How do you change where fire trucks respawn?

[pyrofreak]

I see everyone doing it, and I don't know how to.

For example, I want to remove some of the civilian cars parked behind the police station, and I want to allow some of my own units to park there (when you say return to police station they park their).

Also, (like in 4x4's mod) I want to place some other fire trucks behind each fire station.

So really, I want to know

1.) How to get units to spawn (and report) in a specific location

2.) Allow them to return/park in that location

3.) How to add/remove units from the drop down bar (police/fire/ems/etc)

Thank You.

Edit: If there are any tuts on this point me in that direction, Thank You

[CultziBolzi]

Here Is link for where / how to change spawn place